Regarding “Hints of a flaw in special
relativity” (SN: 10/22/11, p. 18), there
could be a simple explanation for neutrinos being measured as traveling faster
than the speed of light in a vacuum.
While a vacuum is typically defined as a
space entirely devoid of matter, in fact a
vacuum is a busy medium with virtual
particles continually being created and
destroyed. Light passing through a vacuum is affected by such activity.

Neutrinos have such low interactions
that they can pass through a lead wall
several hundred light-years thick without slowing down. The ultimate speed in
the universe is, therefore, that of neutrinos, not photons in a vacuum. It isn’t so
much that neutrinos are faster than light
in a vacuum, rather that light is slower
than neutrinos whether or not the neutrinos are in a vacuum.

As for special relativity, it relies on theconstancy of the speed of light, not on anyparticular speed of light. Substitutingthe burden of outlier data accumulatesenough that someone questions existingparadigms. So while the editorial “Withscientific puzzles, all the pieces have to fit”(SN: 1/28/12, p. 2) was mostly excellent, Iobject strongly to the final phrase, “if itdoesn’t fit, you must omit.” Rather, “if itdoesn’t fit, you must understand why.”Even if the outlier data were in error,understanding the cause will improvefuture experiments. And you never know,maybe it really shouldn’t have fit!Al Bogart, Framingham, Mass.

I am in complete agreement with thereader. I should have stressed that “if itdoesn’t fit, you must omit” is just a gen-eral rule. The rare exceptions are thesource of exciting scientific advances,requiring the creation of a whole newpuzzle. — Tom Siegfriedthe speed of neutrinos would not affectthe measurable results.

Robert Berliner, Los Angeles, Calif.

Such interactions in a vacuum do slow
light down, a phenomenon called the
Scharnhorst effect. But this effect is much
too insignificant to explain how neutrinos
could arrive at a detector 60 nanoseconds
earlier than light in a race covering only
730 kilometers. That 60 nanoseconds
corresponds to a margin of victory in that
race of about 18 meters. A photon slowed
by the Scharnhorst effect would lag
behind a photon without such a slowdown
by only about the width of an atom — after
racing for the current age of the universe.
— Tom Siegfried

While it seems unlikely the faster-than-light neutrinos are really that fast, it is
important to find the cause of the experimental error (if there was an error). Scientific revolutions are the result of years of
ignoring data that “don’t fit” until finally